From f9c2aaad9d1f5ac84e2691c1e9384e7f81b64a8c Mon Sep 17 00:00:00 2001 From: Michal Hlavinka Date: Mon, 8 Jun 2026 12:09:39 +0200 Subject: [PATCH] fix CVE-2026-26740: buffer overflow in EGifGCBToExtension (RHEL-154865) Resolves: RHEL-154865 --- giflib-5.2.1-cve-2026-26740.patch | 13 +++++++++++++ giflib.spec | 8 +++++++- 2 files changed, 20 insertions(+), 1 deletion(-) create mode 100644 giflib-5.2.1-cve-2026-26740.patch diff --git a/giflib-5.2.1-cve-2026-26740.patch b/giflib-5.2.1-cve-2026-26740.patch new file mode 100644 index 0000000..26ddf0b --- /dev/null +++ b/giflib-5.2.1-cve-2026-26740.patch @@ -0,0 +1,13 @@ +diff --git a/egif_lib.c b/egif_lib.c +index 6219af0..5fb458f 100644 +--- a/egif_lib.c ++++ b/egif_lib.c +@@ -689,6 +689,8 @@ int EGifGCBToSavedExtension(const GraphicsControlBlock *GCB, + for (i = 0; i < GifFile->SavedImages[ImageIndex].ExtensionBlockCount; i++) { + ExtensionBlock *ep = &GifFile->SavedImages[ImageIndex].ExtensionBlocks[i]; + if (ep->Function == GRAPHICS_EXT_FUNC_CODE) { ++ if (ep->ByteCount != 4) ++ return GIF_ERROR; + EGifGCBToExtension(GCB, ep->Bytes); + return GIF_OK; + } diff --git a/giflib.spec b/giflib.spec index 22dd705..b57ffc7 100644 --- a/giflib.spec +++ b/giflib.spec @@ -1,7 +1,7 @@ Name: giflib Summary: A library and utilities for processing GIFs Version: 5.2.1 -Release: 10%{?dist} +Release: 11%{?dist} License: MIT URL: http://www.sourceforge.net/projects/%{name}/ @@ -15,6 +15,9 @@ Patch2: giflib_html-docs-consistent-ids.patch # from upstream, for <= 6.1.1, RHEL-154864 # https://sourceforge.net/p/giflib/code/ci/f5b7267aed3665ef025c13823e454170d031c106/ Patch3: giflib-5.2.1-cve-2026-23868.patch +# sent upstream, RHEL-154865 +# https://sourceforge.net/p/giflib/bugs/199/ +Patch4: giflib-5.2.1-cve-2026-26740.patch BuildRequires: gcc BuildRequires: make @@ -80,6 +83,9 @@ rm -f %{buildroot}%{_libdir}/libgif.a %changelog +* Mon Jun 08 2026 Michal Hlavinka - 5.2.1-11 +- fix CVE-2026-26740: buffer overflow in EGifGCBToExtension (RHEL-154865) + * Tue Mar 24 2026 Michal Hlavinka - 5.2.1-10 - fix CVE-2026-23868: double free in GifMakeSavedImage (RHEL-154864)